fix: add cancellation token support

[StevanFreeborn]

closes #33

• fix: copilot first attempt
• fix: cleanup copilot mistakes with passing cancellation token to methods that don't accept them
• chore: upgrade test project to .NET 9
• chore: upgrade dependencies

[Copilot]

Pull Request Overview

This PR adds support for cancellation tokens across all API methods, upgrades both client and test projects to .NET 9, and bumps related dependencies.

• Extend interface and implementation to pass CancellationToken through all requests
• Upgrade target frameworks and package references in test and library projects
• Clean up Copilot-generated method signatures and overloads

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
tests/AnthropicClient.Tests/AnthropicClient.Tests.csproj	Bumped test project to net9.0 and updated package versions
src/AnthropicClient/IAnthropicApiClient.cs	Added optional CancellationToken to all API method signatures and XML docs
src/AnthropicClient/AnthropicClient.csproj	Updated Microsoft.Bcl.AsyncInterfaces and System.Text.Json package versions
src/AnthropicClient/AnthropicApiClient.cs	Propagated cancellation tokens into SendRequestAsync and method overloads

Comments suppressed due to low confidence (4)

src/AnthropicClient/AnthropicApiClient.cs:305

• The ReadResultsAsync() call does not receive the outer cancellationToken, so cancellation won’t propagate into the result stream. Pass the token: ReadResultsAsync(cancellationToken).

return AnthropicResult<IAsyncEnumerable<MessageBatchResultItem>>.Success(ReadResultsAsync(), anthropicHeaders);

src/AnthropicClient/IAnthropicApiClient.cs:99

• The summary for ListAllModelsAsync is identical to ListModelsAsync. Update it to something like Lists all models asynchronously to clarify its behavior.

/// <summary>Lists the models asynchronously</summary>

tests/AnthropicClient.Tests/AnthropicClient.Tests.csproj:1

• [nitpick] New cancellation support should be covered by unit tests. Consider adding tests that assert cancellation requests properly abort ongoing operations for at least one API method.

<Project Sdk="Microsoft.NET.Sdk">

src/AnthropicClient/AnthropicApiClient.cs:306

• [nitpick] The inner generator parameter is named ct, but other methods use cancellationToken. Rename ct to cancellationToken for consistency and readability.

async IAsyncEnumerable<MessageBatchResultItem> ReadResultsAsync([EnumeratorCancellation] CancellationToken ct = default)

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 98.85%. Comparing base (fc2932f) to head (16ee80a).
Report is 12 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #34      +/-   ##
==========================================
- Coverage   98.98%   98.85%   -0.14%     
==========================================
  Files          81       81              
  Lines        1478     1479       +1     
  Branches      126      127       +1     
==========================================
- Hits         1463     1462       -1     
  Misses          5        5              
- Partials       10       12       +2     

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[Copilot]

Pull Request Overview

This PR adds CancellationToken support across the API surface and upgrades to .NET 9, including test and CI dependencies.

• Introduces optional CancellationToken parameters to all client methods
• Updates project SDKs and package references to .NET 9
• Updates CI workflows and editor settings for .NET 9 compatibility

Reviewed Changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
tests/AnthropicClient.Tests/AnthropicClient.Tests.csproj	Upgraded test project to net9.0 and bumped test dependencies
src/AnthropicClient/IAnthropicApiClient.cs	Added CancellationToken overloads and updated XML docs
src/AnthropicClient/AnthropicClient.csproj	Bumped library dependencies to versions compatible with .NET 9
src/AnthropicClient/AnthropicApiClient.cs	Wired CancellationToken through all HTTP calls
.vscode/settings.json	Added new vocabulary for .NET 9 tooling
.github/workflows/pull_request.yml	Switched CI to use .NET 9 SDK
.github/workflows/publish.yml	Switched publish pipeline to use .NET 9 SDK